Horseshoe Crab

Reference

• Recently the Zoological Survey of India (ZSI) and the Odisha Forest Department have signed an agreement for tagging horseshoe crabs on the coast of Odisha state.
• This is the first such effort in the country. Under this, scientists will tag horseshoe crabs in the next three years.

Benefits of tagging

• It will improve understanding of horseshoe crab populations and habitat use, which will be important for conservation and management.
• It can also lead to banning of harmful fishing nets.
  • Although the crab is not part of human diet, its mortality is mainly due to fishing nets. Illegal trafficking and climate change are also threats to the crab.

About Horseshoe Crabs

• These crabs are one of the oldest living creatures on Earth without any morphological changes.
• These crabs have existed for more than 450 million years, meaning they predate the dinosaurs.

Characteristics

• Horseshoe crabs look like prehistoric crabs but are more similar to scorpions and spiders.
• Their body is divided into three parts, the first part is the head or prosoma, the middle part is the abdomen or opisthosoma and the third part is the tail or telson.
• This crab is named 'horseshoe crab' due to its head being round and U-shaped like a horseshoe.
• These crabs have nine eyes all over their body and many other light receptors near the tail.
• They have a hard exoskeleton and 10 legs, which they use to walk on the sea floor.
• Female horseshoe crabs are about one-third larger than males.

Details

• There are three other species of horseshoe crabs around the world: Limulus Polyphemus found around the Americas and two species from India, Tachypleus Gigas and Carcinoscorpius Rotundicauda.
  • Like the Olive Ridley sea turtles, these crabs are basically deep sea creatures.
• Both the species found in India are found on the northeastern coast, especially the coast of Odisha and West Bengal.
  • Carcinoscorpius rotundicauda is found in the Sundarbans mangroves of West Bengal while both Tachypleus gigas and Carcinoscorpius rotundicauda are found in Odisha. In fact, the maximum population of horseshoe crabs is found on the Odisha coast and Balasore is their largest breeding ground.

Medicinal value

• Horseshoe crabs are known for their strong immune system and their blood is very important for the preparation of Rapid Diagnostic Reagents. Also, injections and medicines are tested with the help of these crabs.
• A molecule has been developed from the reagent of horseshoe crabs which will help in treating pre-eclampsia and many babies can be saved in the womb itself.

Conservation

• Included in Schedule 2 under Wildlife Protection Act, 1972
• IUCN Status: Listed as Data Not Sufficient (DD)